The isl_union_map operations always take the existing map and return
a new one but scop_get_reads_and_writes tries to operate on its
parameters in-place. This fails once a re-allocation happens leading
to "interesting" issues (like random segfaults with
-fdump-tree-graphite-details on larger testcases).
Fixed as follows.
Committed as obvious.
Richard.
2017-10-17 Richard Biener <rguent...@suse.de>
* graphite-dependences.c (scop_get_reads_and_writes): Change
output parameters to references.
Index: gcc/graphite-dependences.c
===================================================================
--- gcc/graphite-dependences.c (revision 253811)
+++ gcc/graphite-dependences.c (working copy)
@@ -67,9 +67,9 @@ add_pdr_constraints (poly_dr_p pdr, poly
reads are returned in READS and writes in MUST_WRITES and MAY_WRITES. */
static void
-scop_get_reads_and_writes (scop_p scop, isl_union_map *reads,
- isl_union_map *must_writes,
- isl_union_map *may_writes)
+scop_get_reads_and_writes (scop_p scop, isl_union_map *&reads,
+ isl_union_map *&must_writes,
+ isl_union_map *&may_writes)
{
int i, j;
poly_bb_p pbb;
